This invention concerns an automatic multi-function testing machine for electric appliances, particularly requiring only one worker and largely shortening the time needed for testing many kinds of characteristics.
Generally, electric appliances pass through a series of various tests so as to be provided with quality good enough to be used by consumers before manufacturers send them in market. In conventional testing procedure, a worker at every testing station manually connects contacts of an electric appliance with those of a tester or a meter for one item, with considerable time for testing needed. The more the testing items are, the more the workers are needed. For example, an electric appliance such as a rice cooker should be tested of temperature condition, pressure endurance, insulation, resistance, and power consumed, through the following conventional steps.
1. Temperature test: In this test, electric power of 100 V, 11o V, or 200 V is supplied through the plug of a rice cooker, with two contacts of the cooker being used as testing contacts. Then a temperature sensor is placed inside the cooker, which is then rapidly heated up, letting temperature rise up to a pre-set highest value to to see if a temperature switch of the cooker is readily turned off or not. And it should be tested whether the cooker can be heated up to the desired temperature within a a pre-set period of time, and whether the temperature at turning off of the temperature switch is within permitted scope of error or not. PA1 2. Pressure endurance test: In this test, the rice cooker is not to be powered, but two testing contacts of a pressure tester are to be connected with the two contacts of the rice cooker, with one of them being a metal housing of the cooker and the other being a heater of the cooker (practically the two contacts of the plug of the cooker). Then the pressure tester will indicate the result, the tested value, and it will give out a shrill sound as a warning, if the tested pressure endurance is below the pre-set one. PA1 3. Insulation test: In this test, the cooker is not to be powered, and as the same process in the presure endurance test, two contacts of an insulation tester are to be connected with the two contacts of the cooker. Then the insulation tester will show the result, the tested value. PA1 4. Resistance test: In this test, the cooker is also not to be powered, but the two testing bars of a three-purpose meter are made to contact with the two contacts of the cooker, and the three-purpose meter adjusted to resistance testing will indicate the result, tested value of resistance of the cooker. PA1 5. consumed power test: In this test, the cooker is to be powered, and a watt meter is connected between the cooker and AC power, as a conventional well-known way. The two contacts of the cooker is also the plug of the cooker.
As understood from the above description of the conventional testing procedure, in each stage of testing connecting work of the contacts of the appliance to be tested with those of a tester or a meter has to be done manually, requiring considerable time. In addition, though rice cookers are carried automatically on a conveyer from one testing station to another one, a proper distance should be made to cope with different time needed for each testing. Then not a little time would be wasted in the whole testing.